g used
to-day.

3. _Arkwright's Spinning-frame or Water-frame._ Sir Richard Arkwright
invented, in 1771, a machine that accomplished the whole process of
spinning, the worker merely feeding the machine and tying breaks in the
thread. This machine was run by water-power, thus doing away with
hand-power and allowing the operator to attend entirely to the spinning.

4. _The Mule._ In 1779, Crompton invented a mule, by which threads of a
finer and stronger quality could be spun, and thus made it possible to
weave any grade of cloth.

5. _The Power-loom._ The spinners were now able to keep ahead of the
weavers, till Cartwright invented, in 1785, a power-loom that enabled
the weavers to work faster and use all the thread that the spinners
could make.

6. _The Steam-engine._ These machines were run by hand or water-power.
In 1785, Watts' steam-engine, invented several years before this, was
used in the manufacture of cotton, and manufacturers were now able to
use all the raw material they could get. The use of steam instead of
water-power led to the building of factories in cities, where labour was
plentiful and transportation facilities good. This meant large cities.

7. _The Cotton-gin._ Cotton had to be cleaned of its seeds before it
could be used in the factory. This had to be done by hand, which greatly
hindered the supply of raw material. A good deal of the raw cotton came
from the United States, and the planters there grew no more than could
be cleaned and sold. In 1792, Eli Whitney, an American, invented the
cotton-gin, by which the cotton could be cleaned of its seed very
quickly. Formerly a workman could clean by hand only five pounds of
cotton a week; by the saw-gin five hundred pounds could be cleaned in an
hour. (If a cotton-boll can be procured, the pupils will soon discover
how difficult it is to separate the seeds from the cotton.) More cotton
was then grown, because it could be sold to the factories, and England
was able to get all she required to keep the factories going. It may be
added here that the increase in cotton growing required more hands for
its cultivation; at that time, this meant more slaves; the cotton-gin
was therefore a large factor in the slave troubles in the Southern
States that led to the Civil War.

8. _Coal-mining and Smelting._ These machines were made of iron, and
coal was needed to run the engines and to smelt the iron. There was
plenty of coal in England, but very little was m